The bulk of the wind energy available in the atmosphere is found at altitudes which are not feasible for reaching with tower structures. Hence, the cost of harvesting high altitude energy with wind rotors attached to towers is prohibitive. The present invention vastly reduces the cost of harvesting high altitude wind energy by the provision of a wind rotor attached to a flexible shaft and suspended at great heights above the earth by a lifting body.
Nature has provided a few isolated instances wherein spaced mountain ranges extend thousands of feet above a valley floor, with the mountain peaks or parts thereof being placed in close proximity to one another to enable a cable way to be built thereacross so that the cable can be suspended at a great altitude above the valley floor. Usually, prevailing winds will travel at high velocity between the suspended cable and the valley floor.
Gries (British patent specification No. 489,139) discusses the suspension of a wind driven generator, or dynamo, from captive balloons or kites and transmitting the generated electricity to the surface of the ground. Hence, the lifting body employed by Gries must lift an enormous weight in order that appreciable power may be produced by his dynamo.
Beldimano proposed a suspension cable between spaced towers with a plurality of vertical wind wheels being connected to vertically disposed girders. Each of the girders comprises spaced structure for supporting a wind wheel. The wind wheel reciprocatingly drives a power rod. The load imposed upon the suspension cables and the complexity of the system is substantial.
Smith has proposed the use of a plurality of aerial support means which include gas filled balloons, as well as gas filled aerodynamic lifting devices. The aerodynamic lift augments the buoyant lift of the gas contained therewithin. Smith further proposed augmenting the gas lift with a kite.
Accordingly, the prior art teaches the use of various free aerial lifting bodies, as well as the use of ground supported, stationary structures in order to suspend a generator device within the atmosphere by which power can be generated and transmitted to the surface of the earth. Usually, the generator device is directly attached to the aerial support means, and electrical conductors are run downwardly to the surface of the earth. Others propose suspension of a wind rotor which reciprocates a rod so that a ground supported generator can be actuated. In each of the before mentioned inventions, a tremendous mass must be lifted into the air; and accordingly, each of the prior inventions must be practiced near the surface of the earth. Therefore, the advantage of high altitude wind energy is lost.